First of Many
by Coffee and Prose
Summary: Hitting a certain milestone with their adopted son doesn't go as planned. Part of the Homeward universe. For Castle Fluff Friday.


**Crawling out of my dark, stressful hole of a semester to post this for Fluff Friday because who doesn't love something light and fluffy? Takes place during Homeward between chapters 12 and 13, but can stand on its own, too. **

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"Kate?" His little voice croaked, quiet and uncertain. She turned her face into the pillow, let slip the groan at being woken up.

Loved him to death, but it was early still. This morning had been her only chance to sleep in this week. They were all going to sleep in. Have a late breakfast. Take it easy.

Yet Matthew wasn't deterred. She felt the mattress barely dip under his weight as he crawled on hands and knees between her and Castle until he reached the head of the bed. "Kate?"

Sweet, angelic voice. Please go back to bed for thirty more minutes. "What, bug?" She murmured instead, her eyelids still heavy, sealed shut for now.

She felt Matthew's hearty sigh, knew he was inches from her face. "Are you really awake?" He checked. Persistent child.

She forced her eyes open, settling her gaze on the serious little face looming over her. "What?" It came out more as a growl, no coffee in her yet to tame that side of her.

He held up his thumb and index finger pressed tightly together, pinching something small between them. Her brows furrowed.

"What is that?" Didn't help that her gaze couldn't quite focus.

Matthew pulled a strange face, baring his teeth at her. It only took a second to see the vacant spot between two bottom baby teeth. She gasped, pushing up onto her elbow, but before she could offer any congratulations, Matthew stopped her dead in her tracks.

"It fell _out_!" He sobbed, suddenly distressed - or maybe he'd been on the brink of tears this whole time and she was too tired to see it. "I'm loosing all my teeth."

"Matthew, no." She moaned sympathetically, quickly sitting all the way up.

"Y-yes." He cried, struggling to choke back a sob. Not that it mattered; He could be as loud as he wanted and Castle would still sleep right through it.

"Honey." She murmured, framing his flushed face in her hands, making those watery eyes meet hers. Kate's mind was reeling from his outburst. Had no one ever explained this to him?

Oh.

The thought sacked her in the gut. No, of course not. Who would've done that? If his parents were gone by the time he was four and the system was just shuffling him through until he came here -

"You'll get a new tooth in its place." She told him gently. "Permanent teeth. That's just a baby tooth."

His breath hitched, his choked whine faltering. She watched the news work its way through him and, poor baby, he was a tired mess, too.

"Tell me what happened." She tapped the hand that clutched his tooth. Had it been wiggly? It must have been for a little while. She didn't notice. And he would've kept it to himself, quiet boy that he was. Her heart lurched at the thought of Matthew keeping this anxiety secret from them, bottled up inside him. No wonder it had all just come pouring out.

"I woke up and there was something in my mouth. On my tongue." He explained morosely.

"It was just sitting on your tongue?" She laughed. "And you didn't swallow it?"

Matthew shrugged bashfully, careening forward into her chest. Kate's arms went around him instantly.

"I swallowed a few baby teeth in my sleep as a kid. Only reason I laughed." She explained. Yikes. What would have happened if he woke up to nothing but a sudden gap in his teeth and no evidence? That could've been worse, telling him he'd swallowed a tooth. "There's nothing wrong with that if that happens, I should mention." She tried to peer around the top of his head to see his face, see how he was taking all of this in, but he stayed glued to her.

His first tooth fell out and he came to tell her, even if he was grief-stricken over the incident. He chose to tell her. Kate rested her cheek on the top of Matthew's head and squeezed him tighter. She heard once that children's baby teeth fell out in the order that they came in and having that kind of knowledge about Matthew, about his infancy, filled her up with something joyous. She knew which tooth was his first now and she was here for when it fell out. That was something, at least. She would take all the firsts with him that she could get. Whatever milestones he'd reached before were lost on them, but there was still so much ahead of them, so much she wanted to be there for.

"What happens now?" Matthew's voice was muffled against her shirt.

He meant with gaining new teeth probably, but all Kate could think was _tooth fairy_.

She needed Castle for this. Tooth fairy and Santa Claus and the Easter Bunny... that was Castle's territory. What did a baby tooth earn these days? She had no idea. Hadn't crossed her mind once in the months since Matthew came to them. But Castle would know what to do.

"What happens next is," She eased him back so she could see his face. "We wake up Rick and share the good news."

He nodded seriously, the _good news_ of it all still sinking in. Sweet boy. The world was not over with the loss of a tooth.

He crawled over to Castle and shook his shoulders - so strange how Matthew thought that was a nice way to be woken up. She tucked her lip between her teeth when Castle's eyes flew open wide, panicked and alert, but somehow still adorably sleepy.

"What?" He echoed the same word as Kate and again, Matthew held up his unwilling loss.

"You lost a tooth!" Castle cheered, rallying faster than Kate had been able to. He did it, somehow; he drew the first tight smile out of Matthew when he got one strong arm around the boy and tackle-hugged him into the mattress. "Your first tooth, right?" Castle checked, a big dopey smile on his face that had Kate's heart melting into a puddle.

She watched him take notice of the tears on Matthew's face, the boy's red-rimmed eyes, and she quickly shook her head when Castle turned questioningly to her. Not now. They were fine now that he was awake and ushering joy into the moment. But she'd have to tell him sometime just how beautiful it was to watch Matthew blossom with a father's love. If there was one quality of Castle's that she was most thankful for on this journey of learning their son, it was his uncanny ability to turn Matthew's moods around, to make this lonely little boy feel so special and wanted. Because he was. Oh, he was.

"Do you know what this means?" Castle asked their son. Their sweet, sweet son. Castle's smile was infectious, hauling Matthew's attitude up with it. "This means tonight you get to put this under your pillow for the tooth fairy and when you wake up, the tooth fairy will have left you something special in return for your tooth."

Matthew's expression softened with the wonder of Castle's words. A special surprise just for him. Probably something over-the-top from the "tooth fairy" just for one little baby tooth, but worth it to see Matthew's anxiety ease.

She tucked in against Matthew's back and snaked an arm around his waist, the kid sandwiched between her and Castle. No need to worry anymore, darling boy. It would be alright.

"Does your mouth hurt at all?" Castle thought to ask.

"Uh uh." Matthew hummed. "Hey, don't lose it!"

She lifted her head to see Castle had borrowed the tooth from him.

"I won't." Castle promised.

"Need it." Matthew murmured. "For the tooth fairy."

The thing he'd been so unwilling to let go of and now he couldn't wait to give it up in exchange for something else. She held Castle's gaze over the boy, wanting to convey every ounce of gratitude in just one look. Matthew wasn't the only one he could fill up with hope at a moment's notice. She and Matthew both needed that.

Needed him.

Castle placed the tooth back in Matthew's palm and leaned over to kiss the crown of his head. A comfortable silence settled over the room as Kate felt her eyelids drifting shut. "Let's sleep a little longer." She whispered to her guys, felt Matthew hunker down into the mattress and heard Castle let out a heavy sigh in agreement.

All was well.

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**Thoughts? **


End file.
